1. Field of the Invention
The present invention relates to an image processing apparatus that can be connected to a plurality of information processing apparatuses, wherein the image processing apparatus has a function for transmitting image data to an information processing apparatus selected by a user, a method for controlling the image processing apparatus, and a computer program.
2. Description of the Related Art
When an image processing apparatus equipped with a scanner apparatus is provided in a network environment, the image processing apparatus can be used to scan a document. In this case, a driver installed and operable on a client computer can be generally used by a user of the client computer to operate the image processing apparatus. More specifically, the user who operates the client computer can use a scanner driver to instruct the image processing apparatus to perform scan processing and to acquire image data that is read by the scanner. The processing method described above is generally referred to as “Pull Scan processing.”
On the other hand, the user can operate the image processing apparatus to perform scan processing and cause the image processing apparatus to transmit image data read by the scanner to the client computer. The latter method is also widely known and is referred to as “Push Scan processing.”
Further, as discussed in Japanese Patent Application Laid-Open No. 10-111793, according to another method that is derived from the “Push Scan processing” method, a user can operate the image processing apparatus to activate a driver operable on a client computer to perform the “Pull Scan processing.” The processing method discussed in Japanese Patent Application Laid-Open No. 10-111793 is referred to as “quasi-Push Scan processing.”
In performing the “Push Scan processing” or the “quasi-Push Scan processing”, users are required to select a client computer that serves as a transmission destination of image data by operating an operation panel of the image processing apparatus. Accordingly, the image processing apparatus that can perform the “Push Scan processing” or the “quasi-Push Scan processing” is required to store information relating to one or more client computers.
In this case, to increase the usability of the image processing apparatus, it is desired to prevent a client computer that is not currently operated from being designated as a transmission destination of image data. As a method for realizing the above-described control, it is useful that each client computer periodically transmits a notification to the image processing apparatus. In this case, the image processing apparatus can check an operating status of each client computer referring to the notification periodically transmitted from the client computer. On the other hand, the image processing apparatus can return its own operating status to a client computer in response to a notification received from the client computer. Therefore, each client computer can check the operating status of the image processing apparatus.
In this case, a frequency in transmitting notifications from a client computer to the image processing apparatus, and a total number of client computers are factors that have significance. For example, if one of the client computers transmits notifications to the image processing apparatus every five seconds, the notifications is transmitted twelve times per minute. In this case, the image processing apparatus is required to return responses twelve times per minute. If a total of five client computers transmit notifications to a single image processing apparatus at the same frequency, the image processing apparatus is required to return responses 60 times per minute.
Recently, for a purpose of reducing costs, each image processing apparatus has been required to reduce capacity of a memory installed thereon. Accordingly, many of the recent image processing apparatuses has not been equipped with a mass storage apparatus such as a hard disk. It is, therefore, required to reduce an excess processing load on the image processing apparatus.
To this end, setting an upper limit to restrict the total number of client computers that can be managed by one image processing apparatus is a method for reducing the processing load on the above-described image processing apparatus.
The following method is employable when the upper limit is set to restrict the total number of client computers that can be managed by the image processing apparatus considering the above-described circumstance. More specifically, the image processing apparatus can successively register each client computer that has notified its operating status. When the number of the registered client computers reaches the upper limit, the image processing apparatus can terminate registration of the client computers. In this case, a client computer that later notifies an operating status cannot be registered by the image processing apparatus. The image processing apparatus returns no response to the client computer that was not registered.
However, according to the above-described method for restricting the total number of client computers to be managed by the image processing apparatus, if a user arbitrarily selects a transmission destination of image data via the operation panel of the image processing apparatus, a client computer that the user wants to designate may not be displayed because the client computer that the user wants to designate is not constantly managed as one of the client computers within the upper limit.